1. Field of the Invention
The invention relates to a method and a device for detecting one or more mutation(s) in a nucleic acid fragment in a sample.
2. Brief Description of the Prior Art
Methods are known for screening nucleic acid fragments, in particular DNA fragments, for determined mutations. One method includes the following steps, to be performed in suitable sequence, of:
(a) amplifying the nucleic acid fragment present in the sample;
(b) separating the nucleic acid fragments by means of gel electrophoresis in the presence of a gradient resulting in at least partial melting of the double-stranded nucleic acid fragments formed in step (a), for the purpose of fixing the partially melted nucleic acid fragments at a specific location in the gel; and
(c) detecting the separated nucleic acid fragments. It is known that mutations in the DNA can result in hereditary diseases and/or particular forms of cancer. Demonstrating such a mutation in the DNA in a sample of a patient can therefore be important in establishing whether the patient is a carrier of an abnormal gene responsible for a determined genetic disease, or in making a reliable diagnosis. DNA mutation research can also be important for instance in determining the risk of developing particular types of cancer, designing treatment in the case of tumours, in scientific research into links between diseases and particular genetic defects and in tissue typing.
In order to enable detection of a mutation in a nucleic acid fragment, such as for instance in the DNA, in a sample, the nucleic acid fragment present in the sample, which is usually present in the sample in too small a number of copies or as part of a larger nucleic acid fragment, must first be amplified to obtain sufficient material. Use is generally made for this purpose of conventional amplification techniques, such as for instance PCR. After the amplification step the amplified double-stranded DNA fragments must be separated from each other before they can be detected. For this purpose use is generally made of techniques based on gel electrophoresis. A drawback of the present method however is that both the amplification step and the separation step are time-consuming processes, whereby a great deal of time is required to perform the method. Since large numbers of samples often have to be screened, it is desirable that a method be developed with which a large number of samples can be examined in rapid and simple manner for the presence of one or more mutations in the nucleic acid fragments present in the sample.